Industry-compatible silicon spin-qubit unit cells exceeding 99% fidelity.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40993388.
- Also identified by DOI 10.1038/s41586-025-09531-9 and PMC identifier 12488496.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Among the many types of qubit presently being investigated for a future quantum computer, silicon spin qubits with millions of qubits on a single chip are uniquely positioned to enable quantum computing. However, it has not been clear whether the outstanding high-fidelity operations and long coherence times shown by silicon spin qubits fabricated in academic settings<sup>1-8</sup> can be reliably reproduced when the qubits are manufactured in a semiconductor foundry<sup>9-11</sup>. Here we show precise qubit operation of silicon two-qubit devices made with standard semiconductor tooling in a 300-mm foundry environment. Of the key metrics, single- and two-qubit control fidelities exceed 99% for all four devices, and the state preparation and measurement fidelities reach up to 99.9%, as evidenced by gate set tomography. We report spin lifetime and coherence up to T<sub>1</sub> = 9.5 s, <math xmlns="http://www.w3.org/1998/Math/MathML"> <mrow> <msubsup><mrow><mi>T</mi></mrow> <mrow><mn>2</mn></mrow> <mrow><mo>*</mo></mrow> </msubsup> <mo>=</mo> <mn>40.6</mn> <mspace></mspace> <mi>μ</mi> <mi>s</mi></mrow> </math> and <math xmlns="http://www.w3.org/1998/Math/MathML"> <mrow> <msubsup><mrow><mi>T</mi></mrow> <mrow><mn>2</mn></mrow> <mrow><mi>Hahn</mi></mrow> </msubsup> <mo>=</mo> <mn>1.9</mn> <mspace></mspace> <mi>ms</mi></mrow> </math> . We determine that residual nuclear spin-carrying isotopes contribute substantially to operational errors, identifying further isotopic purification as a clear pathway to even higher performance.